Regarding a process for producing a thermoplastic elastomer composition comprising the step of dynamically cross-linking a rubber and a resin with a specific biaxial extruder:
(1) U.S. Pat. No. 5,847,052A discloses a process for producing a thermoplastic elastomer composition using an olefin copolymer rubber and an olefin plastic; and
(2) U.S. Pat. No. 6,599,981B2 discloses a process for producing an olefin thermoplastic elastomer composition comprising a polyolefin resin and a cross-linked rubber.
Since each of the above-mentioned processes comprises the steps of (i) mixing starting materials in a mixer with one another, thereby forming a mixture, and (ii) supplying the mixture to a biaxial extruder, there is a problem in that each process has the extra step (i) of mixing preliminarily the starting materials prior to the supply of them to the biaxial extruder.